Centrifugal separation method and means



May 28, 1963 T. R. MORTON CENTRIFUGAL SEPARATION METHOD AND MEANS Filed July 20, 1959 4 Sheets-Sheet 1 F l G. I

lllllllll IIIHIIIII I4 INVENTOR THOMAS R. MORTON,

BY ATTORNEYS.

May 28, 1963 1'. R. MORTON 3,

CENTRIFUGAL SEPARATION METHOD AND MEANS Filed July 20, 1959 4 Sheets-Sheet 2 INVENTORZ THOMAS R. MORTON,

ATTORNEYS May 28, 1963 1-. R. MORTON CENTRIFUGAL SEPARATION METHOD AND MEANS 4 Sheets-Sheet 4 Filed July 20, 1959 FIG] INVENTOR THOMAS MORTON,

ATTORNEYS.

United States Patent 3,091,334 CENTRIFUGAL SEPARATION METHOD AND MEANS Thomas R. Morton, Bonne Terre, Mo., assignor to Denver Equipment Company, Denver, Colo., a corporation of Colorado Filed July 20, 1959, Ser. No. 828,115 27 Claims. (Cl. 209-211) This invention relates to methods of separating solids in liquids by centrifugal movement, and to apparatus of the multi-separator type for performing such a separation.

Apparatus of this type employs a centrifugal or vortex action to induce an elevating axial movement of a lighter fraction with progressive descent of a heavier fraction to a lower or bottom discharge. This centrifugal action produces What is termed a vortex separation in which coarser or heavier fractions are thrown to the periphery of the separator chamber while finer or lighter fractions are forced inwardly in such separation, with the finer or lighter fraction elevating and the coarser or heavier fraction descending in the continuous or progressve treatment.

Control of the separation according to size or specific gravity has been determined by outlet size, volume of the separation chamber, and velocity of feed in prior art devices, but such controls do not permit accurate or easy changes during operation. In addition, a particular type of apparatus may be adapted for treatment of one material in an eflicient manner, but will not be effective in the treatment of another material of generally similar characteristics. Consequently, trial and error adjustments are necessary before the operation in stabilized.

It is an object of my invention to provide a selective control in centrifugal separations for initial segregation of a predetermined fine fraction for treatment in one separator or treatment zone and a predetermined coarse fraction for treatment in an associated separator or treatment zone so as to form four distinct products of the separation.

Another object of my invention is to provide a simple, durable and eificient multi-chamber separator having feed dividing means directing coarse and fine fractions into the separations of the respective chambers. means may be operable from outside the apparatus to maintain predetermined splits between coarse and fine fractions.

Still another object of this invention is to provide a simple, economical and efiicient multi-zone centrifugal separation with division of feed prior to reaching the first zone to thereby pass a selected coarse fraction directly into the second treatment zone, while directing a selected fine fraction into said first zone for centrifugal separation of its constituents according to size or specific gravity.

A further object of my invention is to provide a simple, durable and efiicient dual-chamber centrifugal separator having adjustable means for diverting and passing a'predetermined coarse'fraction directly into the second chamher and for directing the remaining fine fraction into the first chamber for separation of their constituent solids, with selective adjustments to vary the fine and coarse divisions according to the requirements of a given treatment.

Yet another object of my invention is to provide a selective water wash of material being subjected to size separation in a centrifugal movement to improve the grade of the discharge products of such separation.

Other objects reside in novel details of construction and novel combinations and arrangement ofpart-s, .all of which will be explained in the course of the following description.

The practice of my invention represents a departure from prior art operations in providing an advanced division of feed coming to the first separation zone with immediate passage of one divsion of the feed into the second zone as the feed thereto, the divided flows thereafter being subjected to the centrifugal separations of the respective zones. Preferably, the initial feed is subjected to a directed flow in which the coarser and finer sizes, or the heavier and lighter solids, are substantially segregated, thereby permitting a physical division of the entering flow vbefore the material is affected by the separating action of the respective zones.

In such treatments, coarser materials require large capacity separators while fine materials may be treated effectively in separators of relatively small diameter. For this reason, the feed is split in the practice of the present invention for eificient treatment of each fraction. Usually, only two treatment zones will be required, but a multi-separation treatment may utilize more than two treatment zones, as will be explained in the course of the following description.

The physical division of flow may be attained by operaticn of an adjustable control .exteriorly of the separator permitting a precise and measured division so as to direct more or less of a given fraction into either chamber. By reason of such division, the fine discharge of one separator will be in a different size or gravity range than the fine discharge of the other separator, and the coarse or heavier discharge of said chambers also will be in different ranges. 'I hus, -four distinct products are discharged from the treatment, although the two fine products or the two coarse products .may be combined as a final product in some treatments.

The practice of my invention will be described with reference to the accompanying drawings illustrating typical embodiments of the features of my invention. In the drawings, in the several views of which like parts bear similar reference numerals,

FIG. 1 is a side elevation of a dual-chamber separator apparatus according to the present invention;

FIG. 2 is -a section taken along the line 2-2, FIG. 1;

FIG. 3 is a fragmentary side elevation similar to FIG. 1', illustrating separator chambers of the same diameter, and another arrangement of feed and water inlets;

FIG. 4 is a fragmentary side elevation like FIG. 3, showing the first separator as being of smaller diameter than the secondseparator, and providing still another arrangement of feed and water inlets;

FIG. 5 is a side elevation of another dual-chamber separator apparatus utilizing cylindrical chambers of different diameter and a variation in feed and water inlet positions;

FIG. 6 is a horizontal section through a three-separator assembly :having a single feed inlet with division of flow approaching the firstand secondseparators; and

FIG. 7 is a similar horizontal section of a two-separator assembly in which the .flow of feed is divided 'by a stationary diversion member.

Referring to the form of my invention shown in FIG. 1, the separator apparatus comprises a unitary assembly of first and secondseparator chambers 12 and 13, which are formed by elongated hollow members or casings. Preferably each member comprises a plurality of flanged sections, boltedtogether to provide water-tight joints, and the flanges having sufficient openings as indicated by the bolts 11 in FIG. 2 to permit attachment of supporting structure as required. Usually, the separator is mounted on suitable framework in an elevated position fitting the flow requirements of the plant in which it is installed.

Separator 12 has an upper outlet comprising a depending tubular portion 14 concentric with the lengthwise axis of the chamber and terminating above the top 15 of the separator in a flanged end 16 permitting attachment of a line (not shown) by which the discharge may be conducted away from the separator-12, although in many treatments the discharge through portion 14 will be open to inspection. As shown, the lowermost section 12x is frusto-conical, flanged at its bottom for connection with a central outlet member 17.

Feed to the unit is supplied by a curved inlet member 19, preferably of diminishing volume in the direction of the separator entrance as shown, and the outside wall 20 of inlet 19 merges with one wall of the conduit means or passage 21 comprising the feed inlet to chamber 13. The feed supply to inlet member 19 will be delivered under sufficient hydrostatic head or pumping pressure to assume a high velocity movement as it approaches chamber 12, and the curvature of the inlet provides a centrifugal sorting action in the approach with coarse sizes or heavier fractions thrown toward wall 20 causing a crowding of fine sizes or lighter fractions toward the opposite inner wall of the inlet.

Chamber 12 is slotted as shown at 22 to provide an entrance for substantially tangential movement of entering feed into the upper portion of chamber 12. An adjustable gate or baffle 23 is supported adjacent the slotted opening 22 on a depending shaft 24 extending through top 15 in a position to intercept and divide the entering feed. A handle 25 at the top of shaft 24 permits selective movement of the bafile to vary the coarse, fines division and direct a predetermined fraction as the feed to chamber 13. Preferably, a scale or other indicia on top 15 registers with the various positions of handle 25 to permit visual selection of the various settings.

Chamber 13 is similar to chamber 12 in functioning, and as shown is of smaller dimension, i.e., lesser diameter and length. It has a central upper outlet 14a flanged at 16a extending through its top 15a, a lower central outlet 17a, and a frusto-conical lower section 13x. The feed directed through inlet 21 moves in a centrifugal flow in chamber 13 with the lighter or finer size fraction being moved inwardly by the formation of a high density body of solids descending along the periphery of the chamber. The light fraction and a major portion of contained liquid are directed in a high velocity movement into tube 14a, and pass from the apparatus as a final product of the separation.

The coarse or heavier fraction and a minor portion of the liquid descend to and out of outlet 17a as another final product of the separation. The accumulation of solids in the descending column provides a sorting action in which fines are displaced inwardly and entrained in the elevating flow through upper outlet 14a. The separation in chamber 13 is very efficient due to initial size segregation of the product constituting the feed to this chamber.

In many operations, a more eflicient separation is at tained in dilute pulps, and if the feed to separator 13 contains too high a proportion of solids to liquid, optimum dilution can be provided by a water introduction through an inlet 27 in the upper portion of chamber 13. In preferred practice, the water is introduced tangentially to and in the direction of the circulation of entering feed in said chamber. The effective elevation of the inlet 27 may be varied and in this arrangement the opening is centered at the same elevation as feed inlet 19 of separator 12. Therefore, the entering stream of water is directed into and through the highest density portion of the circulating fiow, providing the required dilution effect together with washing the solids and suspending entrained lighter constituents to assist the separation.

The apparatus illustrated in FIG. 1 effectively performs the novel method of my invention. This method involves treatment in two associated separation zones, in each of which separation and a centrifugal movement are utilized, with the formation of an inner axially ascending lighter portion and an outer descending heavier portion. Feed to the separators initially is subjected to a segregation of solids according to size or specific gravity, preferably by movement along a curved course, and is divided while approaching the entrance to the first separation zone into fine and coarse fractions with the fine fraction passing into the first zone and with the coarse fraction being passed directly into the second zone and with each fraction directed in a centrifugal movement so as to permit each separation zone to function efliciently in the treatment of a size or gravity segregated fraction.

Provision is made for changing the point of division so as to selectively direct more or less of a given fraction into the respective separation zones. The separation between coarse and fine constituents in each zone is highly efficient as the range of sizes or specific gravities in the feed is substantially less than in conventional treatments and with a larger proportion of constituents of substantially the same size. The provision for varying the point of division enables the operator to maintain substantially optimum separations in each zone despite substantial variations in feed con-tent. Similarly, if excessive wear at the lower outlet changes the effective size of such outlet with resultant increase in discharge rate, a variation in the point of division will permit the operation to proceed efiiciently without shut-down for a considerable time after the change in size of the outlet, which otherwise would result in erratic separation.

From the foregoing it will be evident that the practice of the present invention permits efficient separation over long periods of continuous operation without requiring shut-downs for repair and replacement. The segretation of feed also provides four distinct products of the final separation with distinctive and different properties in each of the fine product discharges and coarse product discharges of the respective separations.

In the preceding description, the terms fine and light fractions have been used synonymously, as have the terms heavy and coarse fractions. The apparatus of the present invention may be utilized in treatments of materials of approximately the same size, but differing in specific gravity, and also in size separations of material of the same or similar specific gravity.

The physical division or split of the feed before it reaches the first separation zone may be utilized to throw constituents exceeding a given specific gravity toward the periphery while constituents of lesser gravity are directed through the entrance of the first chamber. Thereafter, the rate of centrifugal movement and the density in the sorting zone determine what fraction ascends and what fraction descends. Also, these factors determine the proportion of liquid discharging with each said product.

The same type of separation is provided in the second separation zone, and where a more dilute pulp is required, additional liquid will be introduced through inlet 27 and thus provide the required control of the separation in said chamber. If feed fluctuations change the characteristics of the solids content entering the first separation zone; variation in the position of the division member 23 will divert more or less of the heavier fraction to the second zone.

In most treatments, it will be unnecessary to dilute the pulp in the first separation zone, but some pulps will benefit from liquid introduction, either for dilution or as a. wash to remove slimes entrained in the coarser fraction of the separation, and an inlet 28 is provided for such liquid input. Preferably, the point of water introduction will be approximately from the point of feed entrance and the water will be introduced in the direction of circulatory movement so as to obtain dilution without impeding the centrifugal movement. As shown, inlet 28 is at a lower level than inlet 27 of chamber 13.

The separation method just described may be performed effectively in other apparatus, such as shown in FIGS. 3, 4 and 5. In some instances, the size and volume of the fraction directed into the first zone will require large capacity treatment, and the volumetric arrangement of separators shown in FIG. 1 will be preferable. In other treatments, the feed to each chamber will be so apportioned that chambers of equal volume will be utilized. Usually the material delivered into the second separation chamber requires greater capacity than the material in the first separation, and the preferred arrangement will be to have a separator of lesser volume in the first zone and a separator of greater volume in the second zone.

FIG. 3 illustrates another form of dual-chamber separator apparatus which is similar in general arrangement to the form of FIG. 1 but differs in the following respects. The chambers 12c and 130 of this form also have the interconnecting passage 21c with gate 23 dividing the feed to direct the divided coarse fraction directly into chamber 13c. The chambers 12c and 130 are of equal diameter and volume, and water inlets 27c and 280 are at approximately the same elevation as the upper half of feed inlet 190.

FIG. 4 illustrates another modification in which chambers 12d and 13d are interconnected by a passage 21d as previously described and have gate 23' arranged to direct a flow of coarse sizes directly into chamber 13d. In this arrangement chamber 12d is the low capacity unit and chamber 13d is the larger capacity unit, substantially reversing the arrangement shown in FIG. 1. As shown, water inlet 27d is below the center of feed inlet 1911, while water inlet 28d is in approximately the same elevation as in FIG. 3.

FIG. 5 employs an arrangement'of cylindrical separator chambers and is shown as a full unitary assembly to illustrate features of the operating procedure. Two cylindrical separator chambers 42 and 43, each having aplurality of flanged sections secured by bolts 11, are interconnected by a passage 51 corresponding to the passage 21 of FIG. 1. The upper discharge outlet of chamber 42 comprises a depending tubular portion 44 extending in'teriorly through the top 45 and having a flange 46 at its upper end permitting connection with a discharge line (not shown).

The bottom outlet 47 is tubular and discharges to atmosphere. A similar arrangement of outlets is provided for chamber 43, including a tubular member 44a depending from top 45a and having its upper or outer end flanged as shown at 46a. The bottom outlet tube 47a is centrally disposed and functions similarly to outlet 47.

Feed to the unit is supplied through an inlet 49 of the same type as inlet 19 of FIG. 1, having an outer curved wall 50 merging with a wall of passage 51 in the manner previously described. In this form chamber 42 is shown as the small diameter unit and chamber 43 as the large diameter unit. The water inlet 57 of chamber 43 is substantially below the elevation of inlet 49 and passage 53.

In operation, the handle 25 is used to move the gate 23 to a predetermined division point and as the separation progresses in chamber 43, the descending solids passing to outlet 4701 build up a bed of material in the lower end of the chamber which finally forms a conical surface as indicated by the dash lines 60. A similar bed 60 is formed in chamber 42 and even in the conical chamber arrangement of FIG. 1 similar beds will form adjacent the lower outlets.

Some treatments will require division of the material into fractions for treatment in at least three stages, and FIG. 6 illustrates a convenient arrangement for such a treatment. As shown, the initial separator 72 of the series is a larger capacity unit, while the second separator '73 and third separator 74 are of substantially equal diameter and a smaller diameter than separator 72. A continuous feed inlet 79 extends along the succession of separators 72, 73 and 74 and prefer-ably has a curved peripheral surface throughout most of its length to provide a segregation of the feed in the manner previously explained. A diversion member 83, preferably a hinged gate as indicated at 84, is disposed adjacent the entrance 82 of separator 72 to direct a fine fraction into such separator while diverting a coarse fraction into the connecting passage 81 between separators 72 and 73. Another gate 76 is located adjacent the entrance 75 of separator '73 and passes a finer fraction of the coarse material into such separator while the extra-coarse fraction is directed through the connecting passage into the entrance 78 of separator 74 in a tangential flow.

The separators 72, 73 and 74 will be of the type shown in FIG. 1 or 5 and discharge the underflow through the respective outlets 77, 77a and 77b and the overflow passes through upper outlets similar to the outlets 14, 14a of FIG. 1. By proper setting of the gates 83 and 76 a predetermined fraction can be discharged into each of the separators and the capacities of such separators may be varied in accordance with the requirements of the intended split.

FIG. 7 illustrates another arrangement of dual type separators in which the feed inlet 89 is of substantial length and continuously curved to provide a high degree of segregation prior to the first split in advance of the entrance 92 of initial separator 86. In this form the exterior or peripheral wall 90 of inlet 89 is a continuous curve which may be a single curve or a compound curve. Beyond the entrance 92 of chamber 86 a wall 95 of the connecting passage 91 is formed as a reverse curve with a forward extension comprising the diversion member 93, while the rearward or downstream portion merges with the wall of the second separator 87 at the entrance thereto. This arrangement serves to direct a tangential flow of feed into each of the separators 86 and 87 and, due to the long travel of the feed in inlet 89 before reaching the point of diversion, the material is so segregated as to provide an accurate split of the respective fractions with a stationary division member.

In all the forms illustrated, the flanged arrangement of the water inlets permits any one to be capped whenever water input is not required in the treatment, or they may be operated intermittently and otherwise closed during periods of continuous operation. The different elevated positions of these inlets is merely representative of the arrangements which may be utilized, and variations beyond those shown are contemplated in the practice of my invention.

Also, it should be understood that any of the volumetric variations described may be utilized with either the cylindrical or conical forms, and the provision of sectional chambers permits in situ change from cylindrical to conical or vice versa, as required. In addition, variations in water input as previously described may be utilized in obtaining the separation in any of the separators shown in the drawings. Finally, the division of incoming feed to the chambers determines what kind of product is discharged from each chamber.

In order to properly perform the novel method of the present invention, it is necessary to obtain some degree of segregation in the incoming feed so as to affect the nec-' essary division of solids in the entering feed and obtain the distinctive product separation as previously described. However, said segregation may be obtained in different ways, such as by a screening separation and two-product introduction into a feed inlet, but best results are obtained when the feed inlet is arranged to provide the required segregation. Consequently, a conduit providing an arouate or spiraling course is advantageous, and by providing a section of reducing dimension, an accelerated flow is obtained.

Obviously, any arrangement which functions similarly to the curved passage, such as a series of flat angles, or which provides an accelerated flow to assist the segregation, such as non-friction surfaces approaching the entrance, will provide a suitable feed to the first separator. The provision of the adjustable gate as the means for dividing the tflOW of feed is well suited to the practice of my invention but it will be understood that other means for dividing the flow maybe utilized, such as the stationary diversion member of FIG. 7, and the latter may be formed of rubber to permit it to be bent :to vary the point of diversion.

In the arrangement shown in FIG. 1 the shaft 24 is positioned near the point of intersection of the wall of separator 12 and conduit means 21 and the gate 23 in an intermediate pivotal position will be substantially in the plane of the wall of separator 12 as it merges with the wall of conduit 21. The range of movement of gate 23 is limited to provide a tangential flow into chamber 12, in all settings, but variations as indicated by the dash line representations of FIG. 2 provide a substantial variation in the coarse and fine fractions passing to the respective separators.

The portion directed outside the gate by the division. never enters separator 12 and thus passes directly into separator 13. The conduit means 21 are so positioned that the feed entering the entrance opening of separator 13 is actually directed into a reverse curve flow so that a high degree of centrifugal movement is imparted within the separator 1-3 by reason of the impelling effect of the high pressure flow. However, as shown in FIGS. 6 and 7 the conduit means between the first and a subsequent point of diversion may provide tangential input and the same direction of rotation in the plurality of separators.

The drawings illustrate the several forms of separators as being mounted in vertical positions, but it should be understood that it is a well-known practice to position centrifugal separators about horizontal axes, and the separators shown and described herein may be operated in that manner. When so operated, the inlet of the feed tube will be at the top and its discharge outlet at the bottom to provide a gravity assisted flow which assists the size segregation in the inlet member.

While the invention has been described with reference to particular embodiments, there is no intent to limit the concept to the precise details so illustrated except lnsofar as set forth in the following claims.

I claim:

1. In a method of separating solids fractions in a pulp containing fine and coarse solids fractions, the steps of moving such a pulp in at least two size separated portions of coarse and fine solids to a point of diversion adjacent the first of two associated separation zones, said zones being of the cyclone separator type, and generally circular in cross section to form an inner, axially-discharging, lighter portion and an outer heavier portion in centrifugal separation, directing a divided coarse fraction from the point of diversion along a course in a common plane with said first movement directly into said second zone, directing the fine fraction into said first zone in a tangential flow in the common plane, and selectively varying the point of diversion so as to direct more or less of each fraction into the respective zones.

2. In a method of separating solids fractions in a pulp containing light and heavy solids fractions, the steps of moving such a pulp in a centrifugal flow forming streams of light and heavy solids to a point of diversion ad acent the first of two associated separation zones, said zones being of the cyclone separator type, and generally circular in cross section to form an inner, axially-discharging, lighter portion and an outer heavier portion in centrifugal separation, directing a divided heavier fraction from the point of diversion along a course in a common planewith said first movement directly into said second zone, directing the light fraction into said first zone in a tangential flow in the common plane, and selectively varying the point of diversion so as to direct more or less of each fraction into the respective zones.

3. In a method of separating solids fractions in a pulp containing fine and coarse solids fractions, the steps of moving such a pulp in at least two size separated streams to a point of diversion adjacent the first of two associated separation zones, said zones being of the cyclone separator type, and generally circular in cross section to form an inner axially-discharging lighter portion and an outer heavier portion in centrifugal separation, selectively dividing said streams at the point of diversion so as to direct a selectively segregated fine fraction into said first zone along a course in a common plane with said first movement, and directing the divided selectively segregated coarse fraction in the common plane directly into said second zone.

4. In a method of separating solids fractions in a pulp containing fine and coarse solids fractions, the steps of moving such a pulp in at least two size separated streams to a point of diversion adjacent the first of two associated separation zones, said zones 'being generally circular in cross section to form an inner axially-discharging lighter portion and an outer heavier portion in centrifugal separation, selectively dividing said streams at the point of diversion, directing a selectively segregated fine fraction from the point of diversion along a course in a common plane with said first movement directly into said first zone, directing a selectively segregated coarse fraction from the point of diversion in the common plane directly into said second zone, and directing a stream of liquid substantially tangentially into at least one said zone in the flow path of the feed to the zone.

5. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in cross-section, each casing having a separate peripheral feed inlet, a separate outlet for an inner, axially discharging lighter fraction and another separate outlet for an outer, heavier fraction, and means associated with said casings for directing a pulp feed into at least two streams of size segregated pulp constituents flowing in a common plane toward the respective inlets of said casings, including conduit means in said common plane for said streams, and flow dividing means mounted in said conduit means adjacent a first casing for separating said streams so as to direct one flow as the pulp feed in one size range to one said chamber and a second flow as the pulp feed in a different size range to the other said chamber.

6. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in crosssection, each casing having a separate peripheral feed inlet, a separate outlet for an inner, axially discharging lighter fraction and another separate outlet for an outer, heavier fraction, and means associated with said casings for directing a pulp feed into at least two streams of size segregated pulp constituents flowing in a common plane toward the respective inlets of said casings, including conduit means in said common plane for said streams, a flow splitting device extending into said conduit from adjacent a first of the casings for separating said streams so as to direct one flow as the pulp feed in one size range to one chamber and a second flow as the pulp feed in a different size range to the other chamber, said device being adjustable from outside the casings whereby the splitting of the streams may be varied.

7. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in cross-section, each casing having a peripheral feed inlet, an outlet for an inner, axially discharging lighter fraction and another outlet for an outer, heavier fraction, and means associated with said casings for directing feed into at least two size segregated streams flowing in a common plane toward the respective inlets of said casings, including conduit means in said common plane for said streams, and a 9 flow dividing, hinged gate mounted in said conduit adjacent a first casing for separating said streams so as to direct one flow as the feed to a first chamber and another flow as the feed to a second chamber, said hinged gate adapted for selective division of said feed from without said conduit.

8. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in cross-section, each casing having a separate peripheral feed inlet, a separate out-let for an inner, axially discharging lighter fraction and another separate outlet for an outer, heavier fraction, and means associated with said casings for directing a pulp feed into at least two streams of size segregated-pulp constituents flowing in a common plane toward the respective inlets of said casings, a'conduit in said common plane having one wall aligned with the peripheral inlet to a first chamber and an opposite wall merging with an exterior wall of the means for directing said streams in said common plane, division structure mounted in said conduit adjacent a first said casing and arranged to selectively divide said flow so as to divert one flow as the pulp feed in one size range to a first chamber and the balance of the flow as the pulp feed in a different size range to the other chamber.

9. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in crosssection, for the centrifugal separation of solids in liquid, a feed inlet associated with a first casing for delivering a centrifugal flow of pulp through a peripheral opening of said first casing, a feed inlet for the second casing in spaced but proximate relation to the inlet of said first casing, conduit means associated with said second casing arranged as an extension of its feed inlet in substantially the same plane as said first feed inlet and constructed and arranged to deliver a graded portion of pulp feed directly through a peripheral inlet of said second chamber in a centrifugal flow, and means in said conduit adjacent the peripheral inlet of the first casing for dividing the incoming pulp feed into size segregated fractions and directing one separated fraction in a centrifugal flow through said feed inlet of the first casing so as to pass the balance of the segregated fractions directly into said conduit means as pulp feed to the second casing.

10. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in crosssection, for the centrifugal separation of solids in liquid, a feed inlet associated with a first casing for delivering a centrifugal flow through a peripheral opening of said first casing, a feed inlet for the second casing in spaced but proximate relation to the inlet of said first casing, conduit means associated with said second casing arranged as an extension of its feed inlet in substantially the same plane as said first feed inlet and constructed and arranged to deliver a graded portion of feed directly through a peripheral opening of said second chamber in a centrifugal flow, adjustable means in said conduit means adjacent the peripheral opening of said first casing for dividing the incoming feed and directing one separated stream in a centrifugal flow through said feed inlet of the first casing so as to pass the balance of the feed directly into said conduit means as feed to the second casing, and means operable exteriorly of the apparatus for actuating said adjustable means in a selective division of said flow.

11. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in crosssection, for the centrifugal separation of solids in liquid, a curved feed inlet associated with a first casing for segregating solids in size ranges and delivering a centrifugal flow in one segregated size range through a peripheral opening of the first chamber, a feed inlet for the second casing in spaced but proximate relation to the inlet of said first casing, conduit means associated with said second casing arranged as an extension of its feed inlet in substantially the same plane as said curved feed inlet and arranged to deliver a graded portion of feed in a different size range directly through a peripheral opening of said second chamber in a centrifugal fiow, and means mounted in said conduit means adjacent the peripheral opening to said first chamber for dividing the incoming feed according to segregated sizes and directing one stream in a selected size range in a centrifugal flow through said feed inlet of the first casing so as to pass the balance of the feed in another size range directly into said conduit means as feed to the second casing.

12. Apparatus as defined in claim 11, in which the feed inlet diminishes in volume toward the entrance to said first chamber.

13. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in crosssection, each casing having a separate peripheral feed inlet for pulp, a separate outlet for an inner, axially discharging lighter fraction and another separate outlet for an outer, heavier fraction, and means operative-1y associated with the casings for introducing a pulp feed to the respective chamber in separated centrifugal streams of size segregated solids, including conduit means for said streams, division means in said conduit means adjacent a first casing at approximately the same elevation as the inlet thereto, said division means being constructed and arranged to selectively divide the flow in said conduit means into si'ze segregated streams and divert one separated flow as the feed in one size range to one said chamber and a second fiow as the feed inanother size range to a second chamber.

14. In centrifugal separation apparatus of the cyclone separator type, two elongated hollow casings defining separate treatment chambers, generally circular in crosssection, each casing having a separate peripheral feed inlet for pulp, a separate outlet for an inner, axially discharging lighter fraction and another separate outlet for an outer, heavier fraction, means operatively associated with said casings, including a curved conduit for conducting incoming feed in a substantially horizontal, size-segregating, centrifugal fiow in substantially a common plane to the respective treatment chambers, and division means mounted in said conduit adjacent a finst casing and con structed and arranged to divide the incoming flow of feed into selective size ranges and direct one separated flow as the feed in one size range to one said chamber while passing a second flow as the feed in another size range to the other said chamber.

15. In centrifugal separation apparatus of the cyclone separator type, two elongated, hollow, upright casings defining separate treatment chambers, generally circular in cross-section, each having a separate upper outlet for an inner axially ascending lighter fraction and a separate lower outlet for an outer descending heavier fraction, and means operatively associated with said casings for conducting a pulp feed in a size segregating, centrifugal fiow in substantially a common plane into the upper portion of the respective chambers, including conduit means for said pulp feed, and flow splitting means mounted in said conduit means adjacent a first casing and arranged to direct a tangential flow of separated feed in one size range into a second chamber intermediate its ends, said splitting means dividing the flow of incoming, size-segregated feed so as to divert the balance of the separated feed in a difierent size range directly into said first chamber.

16. In centrifugal separation apparatus of the cyclone separator type, two elongated, hollow, upright casings defining separate treatment chambers, generally circular in cross-section, each having a separate upper outlet for an inner axially ascending lighter fraction and a separate lower outlet for an outer descending heavier fraction, means operatively associated with said casings for conducting a pulp feed in a size-segregating, centrifugal flow in substantially a common plane into the upper portion of the respective chambers, including conduit means for said pulp feed, and flow splitting means mounted in said conduit means adjacent a first casing and arranged to direct a tangential fioW of separated feed in one size range into a second chamber intermediate its ends, said splitting means dividing the flow of incoming, size-segregated feed so as to divert the balance of the separated feed in a different size range directly into said first chamber, and manually adjustable means interconnected with the splitting means for dividing the entering flows to the respective chambers into selective size ranges.

17. In centrifugal separation apparatus of the cyclone separator type, two elongated, hollow, upright casings defining separate treatment chambers, generally circular in cross-section, each having a separate upper outlet for an inner axially ascending lighter fraction and a separate lower outlet for an outer descending heavier traction, means operatively associated with said casings for conducting -a pulp feed in a size-segregating, centrifugal flow in substantially a common plane into the upper portion of the respective chambers, including conduit means for said pulp feed, flow splitting means mounted in said conduit means adjacent a first casing and arranged to direct a tangential flow of separated feed in one size range into a second chamber intermediate its ends, said splitting means dividing the flow of incoming, size-segregated feed so as to divert the balance of the separated feed in a difierent size range directly into said first chamber, and means for entering a washing fluid into the pulp feed entering the second chamber.

18. In centrifugal separation apparatus of the cyclone separator type, two elongated, hollow, upright casings defining separate treatment chambers, generally circular in cross-section, each having a separate upper outlet for an inner axial ascending lighter [fraction and a separate lower outlet for an outer descending heavier fraction, means operatively associated with said casings for conducting feed in a centrifugal flow in substantially a common plane into the upper portion of the respective chambers, including conduit means for said feed, flow splitting means mounted in said conduit means adjacent a first casing and arranged to direct a tangential flow of separated feed into a second chamber intermediate its ends, said splitting means additionally dividing the fiow of incoming feed so as to divert the balance of the feed directly into said first chamber, and a fluid inlet through each casing for entering a washing fluid into the entering feed, said fluid inlets being at approximately the same elevation as said conduit means.

19. Apparatus as defined in claim 18, in Which the fluid inlet of said first chamber is at a higher elevation than the inlet of the second chamber.

20. Apparatus as defined in claim 18, in which the fluid inlet of said first chamber is at a lower elevation than the inlet of the second chamber.

21. Centrifugal separation apparatus of the cyclone separator type, comprising two casings defining first and second treatment chambers, generally circular in crosssection and disposed in upright arrangement, each having a separate upper outlet for a separated, inner, axially ascending, lighter fraction and -a separate lower outlet for an outer descending heavier fraction, a horizontally disposed inlet operatively associated with a first casing for delivering incoming pulp feed in one size range into the centrifugal flow into an upper portion of said first chamber, conduit means opening through the casing forming the second chamber and constructed and arranged as an extension of said inlet for delivering a separated portion of the incoming feed in a centrifugal flow directly into the second chamber in substantially the same plane as said feed in a different size range inlet, and means mounted in said conduit means for dividing the flow moving to the first chamber into size-segregated 12 partitions so as to divert a separated portion of the incoming feed through said conduit means into the second chamber.

22. Centrifugal separation apparatus of the cyclone separator type, comprising casings defining separate treatment chambers, generally circular in cross-section and disposed in upright arrangement, each having a separate upper outlet for a separated, inner, axially ascending, lighter fraction and a separate lower outlet for an outer descending heavier fraction, a horizontally disposed inlet operatively associated with a first casing for delivering incoming pulp feed in a size-segregated centrifugal flow into an upper portion of said first chamber, conduit means providing an extension of said inlet for delivering a separated portion of the incoming feed in a centrifugal flow directly into the second chamber in substantially the same plane as said feed inlet, and adjustable means mounted in said conduit means for dividing the flow moving to the first chamber into size-segregated portions so as to divert a separated portion of the incoming feed in one size range into the second chamber.

23. Centrifugal separation apparatus of the cyclone separator type comprising .tWo casings defining separate treatment chambers, generally circular in cross-section and disposed in upright arrangement, each having a separate upper outlet for a separated inner, axially ascending lighter fraction and a separate lower outlet for an outer descending heavier fraction, a horizontally disposed helical inlet for pulp operatively associated with a first casing and directing a size-segregating movement to the entering pulp, conduit means providing an extension of said pulp inlet and arranged for delivering a divided portion of the feed in one size range directly through a peripheral inlet of the second chamber in tangential flow and in substantially the same plane as the helical inlet, and an externally controllable adjustable gate at the for- Ward end of an inner wall of said conduit means for selectively dividing the incoming, size-segregated feed into two separated streams for delivery into the respective chambers.

24. Centrifugal separation apparatus of the cyclone separator type comprising two casings defining separate treatment chambers, generally circular in cross-section and disposed in upright arrangement, each having a separate upper outlet for passing a separated inner, axially ascending lighter fraction and a separate lower outlet for passing an outer descending heavier fraction, a horizontally disposed helical inlet for pulp operatively associated with a first casing and directing a size-segregating movement to the entering pulp, conduit means providing an extension of said pulp inlet and arranged for delivering a divided portion of the feed in one size range directly through a peripheral inlet of the second chamber in tangential flow and in substantially the same plane as the helical inlet, means upstream from said conduit means for selectively dividing the size-segregated feed to the respective chambers into separated streams flowing in substantially a common plane, and a water inlet in at least one of said casings at approximately the same elevation as said feed inlet.

25. In centrifugal separation apparatus of the cyclone separator type, a casing structure forming two separate treatment chambers generally circular in cross-section, each having a separate outlet at one end for an axially discharging lighter fraction and a separate outlet at its opposite end for a heavier fraction, a feed inlet for pulp associated with the casing structure and arranged to maintain the feed in size segregated fractions and to deliver separated fractions of incoming feed in diflerent size ranges into each of said treatment chambers in separated streams flowing in substantially a common plane, and means associated with said feed inlet for selectively dividing the incoming feed into said separated streams prior to the introduction of said streams into the respective chambers.

13 26. Apparatus as defined in claim 25, including at 2,701,056 least three chambers and at least two lfeed dividing 2,836,287 means. 2,910,178

27. Apparatus as defined in claim 25 in which the feed inlet is curved and arranged to introduce the feed into 5 said chambers for rotation in opposite directions. 527 502 References Cited in the file of this patent UNITED STATES PATENTS 2,658,618 Vogel Nov. 10, 1953 10 14 Morton Feb. 1, 1955 Croley May 12, 1959 Bonneau Oct. 27, 1959 FOREIGN PATENTS Belgium Apr. 15, 1954 OTHER REFERENCES Dorr-Oliver Bulletin No. 2503, 1955, page 4. 

5. IN CENTRIFUGAL SEPARATION APPARATUS OF THE CYCLONE SEPARATOR TYPE, TWO ELONGATED HOLLOW CASINGS DEFINING SEPERATE TREATMENT CHAMBERS, GENERALLY CIRCULAR IN CROSS-SECTION, EACH CASING HAVING A SEPARATE PERIPHERAL FIXED INLET A SEPARATE OUTLET FOR AN INNER, AXIALLY DISCHARGING LIGHTER FRACTION AND ANOTHER SEPARATE OUTLET FOR AN OUTER, HEAVIER FRACTION, AND MEANS ASSOCIATED WITH SAID CASINGS FOR DIRECTING A PULP FEED INTO AT LEAST TWO STREAMS OF SIZE SEGREGATED PULP CONSTITUENTS FLOWING IN A COMMON PLANE TOWARD THE RESPECTIVE INLETS OF SAID CASINGS. INCLUDING CONDUIT MEANS IN SAID COMMON PLANE FOR SAID STREAMS, AND FLOW DIVIDING MEANS MOUNTED IN SAID CONDUIT MEANS ADJACENT A FIRST CASING FOR SEPARATING SAID STREAMS SO AS TO DIRECT ONE FLOW AS THE PULP FEED IN ONE SIZE RANGE TO ONE SAID CHAMBER AND A SECOND FLOW AS THE PULP FEED IN DIFFERENT SIZE RANGE TO THE OTHER SAID CHAMBER. 